This invention relates to a communication system call coverage arrangement, and more particularly to coverage arrangements which allow flexibility in answering stations.
One problem inherent in designing communication systems is that incoming calls to one station frequently must be rerouted to other stations under a variety of circumstances which include the original called station being unavailable because the called subscriber is otherwise busy or because the called subscriber is absent from the station set. In this situation it is desirable to have the incoming calls of one station answered or covered by another station.
A problem is that if the station to be covered (the called station) has more than one line then the covering station must have the ability to handle all of these lines in order to provide comprehensive coverage. In addition to causing large wiring problems in hardwired systems a further problem exists when the covering station is required to cover a multiplicity of stations. In such a situation the coverage station requires a large number of line appearance buttons thereby necessitating a telephone set in the nature of a call director set. A further problem is that in call coverage situations it is often desirable to have the main station ring for a given number of cycles prior to the coverage station becoming disturbed. It is also important that the main station have access to a call which has been covered by another station during the progress of the covered call. Thus, systems which have call coverage should be arranged to allow the original called station to retrieve the call, even during an "answered" call.
A compounding problem in call coverage situations is that whenever a station is moved or has a line reassignment it is also necessary to rearrange the coverage station and thus it is a general object of our call coverage arrangement to solve the above discussed problems, and it is a more specific object to accomplish station rearrangements without physical movement and without disrupting service.
A further object in designing call coverage arrangements is that some of the coverage stations may be in to the called station and thus it is not necessary to provide additional ringing but when the coverage telephone is physically separated, ringing as well as visual signals must be provided.